Envelop



F.FISCHER.

(No Model.)

ENVELOP.

Patented Feb. 16, 1897.

'VENTUR E'scl e r Fran/6 BY Wwfli ATTY'S.

. UNITED STATES PATENT OFFICE.

FRANK FISCHER, OF PATERSON, NElV JERSEY.

' ENVELOP.

SPECIFICATION forming part of Letters Patent No. 577,129, dated February16, 1897.

Application fil d December 15, 1896. Serial No. 615,731. (No model.)

To all 1071,0712, it mm/ concern..-

Be it known that I, FRANK FISCHER, a subject of the Emperor of Germany,residing in Paterson, county of Passaic, and State of New Jersey, haveinvented certain new and useful Improvements in Envelops; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings, and to letters of reference marked thereon, whichform a part of this specification.

My invention relates to envelops so con structed as to renderclandestine openin g impossible. Its object is to provide envelopsanswering the above purpose of simple c011- struction and which can beeasily manufactured and will not be more expensive than ordinarymailing-envelope.

The invention consists in certain details of improvement and inthe'combination of parts, substantially as will be hereinafter morefully described, and finally embodied in the clauses of the claim.

In the accompanying drawings, Figure 1 represents the blank of myimproved envelop spread open; Fig. 2, a back view of my improved envelopwith its closing-flap opened, and Fig. 3 an enlarged central sectionalview of the envelop when closed.

.In said drawings, a represents the body of the envelop, having the sideflaps b b, the lower flap 6, and the upper flap d. The side flaps b,with their projecting portions 0, are provided at their lower edges withtongues 0, having their curved edges incised, as at 0 and adapted, whenthe flaps are folded together, as in Fig. 2, to form a segmental-shapedtongue to correspond substantially in shape and size to the curvedportion cl of the upper flap d.

The lower flap c is provided with a substantially V-shaped incision c,the sides of which are preferably parallel to the edges of the said flapand are of a size large enough to permit the insertion of the curvedportion d of the upper flap cl. 1

A cord g'is placed within one of the folds of the envelop andis securedthereto by glue or in anydesired manner. Said cord projects beyond therespective edges of the envelop and will facilitate the opening of thesame, as will be manifest.

The upper flap is covered along its inner edge with an adhesivesubstance, which when folded will fall on the edges of the lower fiapand its curved portion d after being inserted through the cut orincisione exactly upon the incised edges 0 c of the tongues c c, to which itadheres.

The inner edge of the V-shaped flap 6 formed by the incision e, is alsoprovided with an adhesive substance, which, when moistened, will adhereto the outer surface of the upper flap d, as will be manifest.

From the foregoing it can be seen that the envelop when once closedcannot be opened clandestinely, as the incised edges of the tongues 0would necessarily be torn off. Furthermore, additional safety isrendered the envelop by having the upper flap penetrating the lowerflap.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, isv 1. The combination with the side flaps ofan envelop, of a curved tongue projecting from each of said flaps andhaving their edges incised, substantially as and for the purposesdescribed.

2. In an envelop, the combination with the side flaps and the upperflap, of a curved tongue proj ecting from the lower edges of each sideflap and having their curved edges incised, said tongues when foldedtogether to correspond substantially in shape and size to the curvedportion of the upper flap and to be engaged thereby, substantially asdescribed.

3. In an envelop, the combination with the side flaps, the upper flapand the lower flap, of a curved tongue projecting from the lower edgesof each side flap and adapted to be engaged by the inner surface of thecurved portion of the upper flap, and a substantially V- shaped flapformed within the lower flap by a V-shaped incision, and adapted toengage the outer surface of the curved portion of the upper flap,substantially as and for the purposes described.

4. The combination with the flaps of an ensubstantially as and for thepurposes de- IO scribed.

In testimony that I claim the foregoing I have hereunto set my hand this11th day of December, 1896.

FRANK FISCHER. W'itnesses:

ALFRED GARTNER, DUNCAN M. ROBERTSON.

